A lone female Indiana bat was found just over a half mile from the $31 million proposed Interstate 80 interchange south of Waukee.

The bat is considered endangered by state and federal agencies.

Federal officials have asked for a study to determine whether the Indiana bat population would be harmed by the interchange construction.

"We have so much invested in that project already," said West Des Moines Mayor Steve Gaer.

The discovery of the bat won't kill plans for the interchange, but it comes as the cities were preparing to start working on a final design. Officials said the bat was found near Mills Civic Parkway.

The wildlife study of the area is expected to cost about $30,000.

"It simply identifies the areas that are most sensitive to the bat, and we work with whomever is doing the project to minimize the impacts of those areas," said Kraig McPeek of the U.S. Fish and Wildlife Service.

City officials said it's not the cost, but the timing of the study that frustrating.

"If it was needed we would have rather done it years ago when we built the bridge, and then we could have addressed it at that time," said Gaer.

The study has to be done in May because bats are done hibernating then.

"What it would entail is what they call using mist nets or fine mesh nets, stringing them up in the evening night hours and basically capturing bats," said McPeek.

Officials want to have the construction begin later this year.

If bats are discovered the project could be delayed four or five months because the city has to come up with a mitigation plan.

"We hate for it to miss another construction season, if we can help it," said Gaer.